Minimization of Inverse Inlet Flow and Consequent Reduction in Specific Fuel Consumption in Gasoline Engines

1984 ◽  
Author(s):  
Longbao Zhou ◽  
Changgui Yao ◽  
Zhongji Yang
Volume 1 ◽  
2004 ◽  
Author(s):  
G. B. Parvate-Patil ◽  
H. Hong ◽  
B. W. Gordon

The objective of this paper is to the study effects of Late Intake Valve Closing (LIVC), and how it affects the in-cylinder fluid flow for four stroke gasoline engines. Further investigation of LIVC has been performed with the help of an engine cycle simulation program (GT-Power). Study shows that LIVC is beneficial for reduction of pumping losses, which may reduce the break specific fuel consumption (BSFC) of the engine. In this paper, a simulation of LIVC was achieved by retarding the timing of the solenoid actuated intake valve.


Author(s):  
R. K. Mandloi ◽  
A. Rehman

In the present scenario, the designs of S I engine being used in automotives by various manufacturers are not properly suitable to Indian climate condition. India is among those tropical countries where the variation in the temperature is having very vast range i.e. from 0°C to 50°C in various regions of the country. Looking in to this vast varying temperature range, it is very difficult to say that which temperature is most suited for operating condition of engines and will give the best performance levels as far as SFC & BP is concerned. In this work, it has been tried to investigate the best option to run the SI engine and simultaneously to maintain the emission norms. Today research and development in the field of gasoline engines have to face double challenge; on one hand, fuel consumption has to be reduced, while on the other hand, even more stringent emission standard have to be fulfilled. The development of engines with its complexity of in-cylinder process requires modern developed tools to exploit the full potential in order to reduce fuel consumption. There are many strategies for improving fuel economy and reducing exhaust emission HC & CO. The experimental study is carried out on a three cylinders, four stroke, petrol, carbureted, water cooled engine test rig connected to eddy current type dynamometer. The objective of this work was to examine engine performance parameter i.e. specific fuel consumption (SFC), brake power (BP) and also exhaust emission on Varying Engine Temperature at 50, 60, 70, 80° C and at an engine speed of 1500, 2000, 2500 rpm with respect to engine load 6, 9, 12 kg. The results are shown by various graphs with effect of engine temperature on specific fuel consumption, brake power, engine speed, engine load and emission levels of Nox, HC, CO for gasoline and LPG to improve fuel consumption.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Ali Dinc ◽  
Yousef Gharbia

Abstract In this study, exergy efficiency calculations of a turboprop engine were performed together with main performance parameters such as shaft power, specific fuel consumption, fuel flow, thermal efficiency etc., for a range of flight altitude (0–14 km) and flight speeds (0–0.6 Mach). A novel exergy efficiency formula was derived in terms of specific fuel consumption and it is shown that these two parameters are inversely proportional to each other. Moreover, a novel exergy efficiency and thermal efficiency relation was also derived. The relationship showed that these two parameters are linearly proportional to each other. Exergy efficiency of the turboprop engine was found to be in the range of 23–33%. Thermal efficiency of the turboprop engine was found to be around 25–35%. Exergy efficiency is higher at higher speeds and altitude where the specific fuel consumption is lower. Conversely, exergy efficiency of the engine is lower for lower speeds and altitude where the specific fuel consumption is higher.


Author(s):  
Dimitrios T. Hountalas ◽  
Spiridon Raptotasios ◽  
Antonis Antonopoulos ◽  
Stavros Daniolos ◽  
Iosif Dolaptzis ◽  
...  

Currently the most promising solution for marine propulsion is the two-stroke low-speed diesel engine. Start of Injection (SOI) is of significant importance for these engines due to its effect on firing pressure and specific fuel consumption. Therefore these engines are usually equipped with Variable Injection Timing (VIT) systems for variation of SOI with load. Proper operation of these systems is essential for both safe engine operation and performance since they are also used to control peak firing pressure. However, it is rather difficult to evaluate the operation of VIT system and determine the required rack settings for a specific SOI angle without using experimental techniques, which are extremely expensive and time consuming. For this reason in the present work it is examined the use of on-board monitoring and diagnosis techniques to overcome this difficulty. The application is conducted on a commercial vessel equipped with a two-stroke engine from which cylinder pressure measurements were acquired. From the processing of measurements acquired at various operating conditions it is determined the relation between VIT rack position and start of injection angle. This is used to evaluate the VIT system condition and determine the required settings to achieve the desired SOI angle. After VIT system tuning, new measurements were acquired from the processing of which results were derived for various operating parameters, i.e. brake power, specific fuel consumption, heat release rate, start of combustion etc. From the comparative evaluation of results before and after VIT adjustment it is revealed an improvement of specific fuel consumption while firing pressure remains within limits. It is thus revealed that the proposed method has the potential to overcome the disadvantages of purely experimental trial and error methods and that its use can result to fuel saving with minimum effort and time. To evaluate the corresponding effect on NOx emissions, as required by Marpol Annex-VI regulation a theoretical investigation is conducted using a multi-zone combustion model. Shop-test and NOx-file data are used to evaluate its ability to predict engine performance and NOx emissions before conducting the investigation. Moreover, the results derived from the on-board cylinder pressure measurements, after VIT system tuning, are used to evaluate the model’s ability to predict the effect of SOI variation on engine performance. Then the simulation model is applied to estimate the impact of SOI advance on NOx emissions. As revealed NOx emissions remain within limits despite the SOI variation (increase).


Author(s):  
Teja Gonguntla ◽  
Robert Raine ◽  
Leigh Ramsey ◽  
Thomas Houlihan

The objective of this project was to develop both engine performance and emission profiles for two test fuels — a 6% water-in-diesel oil emulsion (DOE-6) fuel and a neat diesel (D100) fuel. The testing was performed on a single cylinder, direct-injection, water-cooled diesel engine coupled to an eddy current dynamometer. Output parameters of the engine were used to calculate Brake Specific Fuel Consumption (BSFC) and Engine Efficiency (η) for each test fuel. DOE-6 fuels generated a 24% reduction in NOX and a 42% reduction in Carbon Monoxide emissions over the tested operating conditions. DOE-6 fuels presented higher ignition delays — between 1°-4°, yielded 1%–12% lower peak cylinder pressures and produced up to 5.5% lower exhaust temperatures. Brake Specific Fuel consumption increased by 6.6% for the DOE-6 fuels as compared to the D100 fuels. This project is the first research done by a New Zealand academic institution on water-in-diesel emulsion fuels.


Author(s):  
A A Abdel-Rahman ◽  
M K Ibrahim ◽  
A A Said

This paper discusses the possibility of improving the part load performance of diesel electric turbocharged engines operating at constant speed conditions. A sequential turbocharged system is proposed, where the compressors are connected In series. The study focused on two turbocharged diesel–electric generating sets existing at Ameria Petroleum Refining Company in Alexandria, Egypt. The results of the prediction showed that, at part load, both the maximum pressure and temperature were increased, and the brake specific fuel consumption was reduced considerably (by about 10 per cent).


Author(s):  
Adel Ghenaiet

This paper presents an evolutionary approach as the optimization framework to design for the optimal performance of a high-bypass unmixed turbofan to match with the power requirements of a commercial aircraft. The parametric analysis had the objective to highlight the effects of the principal design parameters on the propulsive performance in terms of specific fuel consumption and specific thrust. The design optimization procedure based on the genetic algorithm PIKAIA coupled to the developed engine performance analyzer (on-design and off-design) aimed at finding the propulsion cycle parameters minimizing the specific fuel consumption, while meeting the required thrusts in cruise and takeoff and the restrictions of temperatures limits, engine size and weight as well as pollutants emissions. This methodology does not use engine components’ maps and operates on simplifying assumptions which are satisfying the conceptual or early design stages. The predefined requirements and design constraints have resulted in an engine with high mass flow rate, bypass ratio and overall pressure ratio and a moderate turbine inlet temperature. In general, the optimized engine is fairly comparable with available engines of equivalent power range.


2015 ◽  
Vol 82 ◽  
pp. 96-102 ◽  
Author(s):  
Sebastiano Breda ◽  
Fabio Berni ◽  
Alessandro d’Adamo ◽  
Francesco Testa ◽  
Elena Severi ◽  
...  

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